A controlled trial of photochemotherapy for persistent palmoplantar pustulosis.

Twenty-two patients with bilaterally symmetrical persistent palmoplantar pustulosis were treated on one randomly selected side with oral psoralen and long-wave ultraviolet light. The treated side cleared completely in twelve patients, almost cleared in five patients and improved in four. One patient improved on both sides. Fifteen of the twenty-two patients were then treated with topical psoralen and long-wave ultraviolet light on the side that had previously been used as a control. Similar results were obtained. Seven patients cleared completely, six patients were much improved and two were improved. These results are significantly different from those liable to occur by chance (P < 0.001).